The Liver Center of the University of California, San Francisco is an inter-disciplinary consortium of basic and clinical scientists dedicated to understanding the biology and pathobiology of the liver and the treatment of liver diseases. From its inception in 1975, it has undergone continual evolution to meet current scientific challenges, with its Executive Committee monitoring research progress and creating initiatives to open up new areas. The main lines of Center research at present are represented by five inter-related themes: (1) Immunology; (2) Metabolism, Injury and Repair; (3) Genetics and Development; (4) Liver Cancer; and (5) Viral hepatitis. Three themes-Immunology, Genetics and Development, and Liver Cancer-have emerged during the current funding period through recruitment of new members and alliances with organized research units. A major initiative over the past two years has involved the UCSF Cancer Center and resulted in preparation of an application for an NCI SPORE in liver cancer. The Center supports four core facilities: (1) Cell and Tissue Biology; (2) Clinical and Translational Research; (3) Microscopy and Advanced Imaging; (4) Molecular Analysis. The four scientific Cores not only provide direct research support but are a venue for new collaborations and an entry point for new members. Finally, the Center fosters scientific exchange through a Visiting Scientist Program, a Seminar Series, and its Annual Scientific Retreat. In the 2000-01 academic year, these programs brought five leading researchers in basic biology or translational science whose work has particular relevance to the research themes of the Center. The Center continues to expand its support of member science through strategic partnerships, most recently with the Veterans Administration, the UCSF Cancer Center, and the graduate program in Biomedical Sciences. In addition to these affiliations, the Center enjoys close links with the UCSF programs in Immunology and Developmental Biology, respectively. Its funding base continues to grow, and support from the institution is sustained and strong. The opportunities in basic biology and in the application of basic science to clinical liver disease have never been greater, and the Center is poised to catalyze discovery in these areas.